Method for improving access performance on track with re-allocation sector in a hard disk drive

Abstract

A hard disk drive replaces a defective sector with a spare sector. When accessing a track having the defective sector, all normal sectors except for the defective sector are formerly accessed and then, a re-allocation sector which has replaced the defective sector is later accessed. In this manner, the number of searches is reduced during reading/writing (accessing) a track having defectives, thereby improving a data transmission of a hard disk drive.

What is claimed is: 
     
       1. A method for improving data access operation of a hard disk drive, comprising the steps of: determining whether a track of a recording medium written on and read by said hard disk drive contains a defective sector;   when the track of the recording medium contains said defective sector, re-allocating said defective sector with a re-allocation sector from a re-allocation area of said recording medium;   identifying as normal sectors any sector of the recording medium that is not determined to be a defective sector;   using a primary buffer pointer and a secondary buffer pointer within a memory of said hard disk drive to access all normal sectors of the recording medium, by using said primary buffer pointer to access all sectors of the recording medium preceding said defective sector and using said secondary buffer pointer to access all sectors of the recording medium following said defective sector; and   when the track containing said defective sector is being accessed during one of a read and a write operation, accessing all normal sectors of said track except for said defective sector, and then, accessing said re-allocation sector and replacing said defective sector.   
     
     
       2. The method of claim 1, wherein said primary buffer pointer has a start address and an end address of buffer areas in said buffer memory, said end address corresponding to the sector preceding said defective sector. 
     
     
       3. The method of claim 1, wherein said buffer memory has buffer areas for storing addresses of sectors of a current track of said hard disk drive. 
     
     
       4. The method of claim 1, further comprising the steps of: transferring data, during the read operation, from the normal sectors and sequentially storing by address to a buffer memory while skipping an address of said buffer memory corresponding to said defective sector and then transferring data from said re-allocation sector to the skipped address of said buffer memory; and   sequentially transferring by address during the read operation all data stored in said bluffer memory to a host computer.   
     
     
       5. The method of claim 4, further comprising the steps of: transferring data during the write operation, from the host computer to said buffer memory, said buffer memory storing data sequentially by address;   writing the data stored in said buffer memory to the corresponding normal sectors of a track while skipping the buffer memory corresponding to said defective sector and then writing the buffer memory corresponding to said defective sector to said reallocation sector; and   verifying that the writing of the data to said hard disk drive is completed.   
     
     
       6. A method for allocating defective sectors in a disk drive, comprising: using a buffer memory with buffer areas for storing address data of sectors of a current track of a recording medium, and using primary and secondary buffer pointers to address sectors of the current track of said recording medium;   setting said primary buffer pointer with a starting address and an ending address of buffer areas in said buffer memory;   setting said secondary buffer pointer with a starting address of a designated buffer area in said buffer memory corresponding to a sector following a defective sector of the current track;   reading information data from the sector of the current track set in accordance with the starting address and the ending address of said primary buffer pointer;   determining whether the sectors from which the information data is read contain a defective sector;   when the sector from which the information data is read is a defective sector, skipping said defective sector;   reading information data from the sector of the current track set in accordance with the starting address of said secondary buffer pointer, and storing read data beginning at said designated area of said buffer memory;   searching a re-allocation sector that has replaced said defective sector;   reading information data from the re-allocation sector, and storing read data in a buffer area that an address following the ending address of said primary buffer pointer is set; and   transferring all information data stored in said buffer memory to a host computer.   
     
     
       7. The method of claim 6, further comprising the steps of: transferring information data from said host computer to said buffer memory;   writing the information data stored on said buffer memory to the sector of a track in accordance with the starting address and the end address of said primary buffer pointer;   when the end address of said primary buffer pointer is reached, the next buffer area corresponding to said defective sector is skipped;   writing the information data to the sector of a track in accordance with the starting address of the secondary buffer pointer;   verifying that the writing of information to said recording medium is completed;   searching a re-allocation sector that has replaced said defective sector; and   writing the information data from a buffer area of said buffer memory to the re-allocation sector, the buffer area of said buffer memory corresponding to the address following the end address of said primary buffer pointer.   
     
     
       8. The method of claim 6, further comprising the step of verifying the completion of the data read after reading information data from the sector of the current track set in accordance with the starting address of said secondary buffer pointer. 
     
     
       9. A hard disk drive, comprising: a magnetic disk having a plurality of concentric tracks with sectors;   a head accommodating reading and writing data transferred from a host computer from/to said magnetic disk;   a buffer memory with buffer areas accommodating storing address data of sectors of a current track of said magnetic disk, and primary and secondary buffer pointers to address sectors of the current track of said magnetic disk; and   a controller accommodating controlling data read and write operations and minimizing the number of searches of tracks containing defective sectors during said data read and write operations by: determining whether a track of a recording medium contains a defective sector;   when the track of the recording medium contains said defective sector, re-allocating said defective sector with a re-allocation sector from a re-allocation area of said magnetic disk; and   when the track containing said defective sector is being accessed during one of said data read and write operation, controlling said primary and secondary buffer pointers to access all normal sectors of said track except for said defective sector, and then, access said re-allocation sector which has replaced said defective sector to improve data transmission of said hard disk drive.     
     
     
       10. A method, comprising the steps of: setting a primary pointer with a starting address and an end address of buffer areas in a memory of a recording medium;   setting a secondary pointer with a starting address of a designated buffer area in said memory corresponding to a sector following a defective sector of a current track of said recording medium;   transferring information data from a computer to said memory;   writing the information data stored on said memory to a sector of a track in accordance with the starting address and the end address of said primary pointer;   when the end address of said primary pointer is reached, the next buffer area corresponding to said defective sector is skipped;   after skipping said defective sector, writing the information data to the sector of a track in accordance with the starting address of the secondary pointer;   searching for a re-allocation sector that has replaced said defective sector; and   writing the information data from a buffer area of said memory to said re-allocation sector, the buffer area of said memory corresponding to the address following the end address of said primary pointer.   
     
     
       11. The method of claim 10, further comprising the step of verifying that the writing of information data to said recording medium is completed after writing information data from the sector of the current track set in accordance with the starting address of said secondary pointer. 
     
     
       12. The method of claim 11, wherein writing the information data stored on said memory to the sector of a track is controlled by a controller unit of said recording medium.